Federal Watchdog Finds Dental and Vision Insurance Markets Dominated by Few Insurers

About one in four Americans carries stand-alone dental or vision insurance, yet in many states they have precious few insurers to choose from. A federal watchdog report released this week finds the markets are heavily concentrated, with a small number of companies commanding commanding dominant shares of enrollment across much of the country.

The Government Accountability Office report, GAO-26-107787, titled "Private Dental and Vision Insurance: Market Concentration Varied Among States," was published March 9, 2026. An accompanying GAO WatchBlog post, "Why Fewer Insurers in Dental and Vision Markets Could Matter to You," brought the findings to a broader audience.

The GAO examined two questions: how concentrated and vertically integrated these markets are, and what is known about the effects of that concentration on competition. Auditors analyzed 2024 enrollment data from the National Association of Insurance Commissioners, described as the most recent available at the time of the analysis. The performance audit ran from August 2024 through March 2026.

The concentration figures are striking. In the dental group insurance market, the three largest insurers in a given state control between about 38 percent and about 98 percent of enrollment, depending on the state. The vision group market tells a similar story: the three largest insurers hold between about 41 percent and 96 percent of enrollment, with a median of roughly 77 percent. The individual vision market is even more lopsided, with the three largest insurers controlling between about 56 percent and nearly 99 percent of enrollment in a given state, at a median of about 78 percent.

"The concentration of a market refers to the degree to which a small number of companies control a large part of the market," the GAO noted in its report, underscoring that high concentration may reduce competition.

Beyond raw market share, the GAO also examined vertical integration, a structure in which a single company controls multiple links of the supply chain. In vision care, that can mean a company simultaneously owns the insurer, the eye doctor's practice, and the manufacturer of lenses and frames. In some cases, companies also operate retail optical brands and optical laboratories. Studies suggest such arrangements may generate efficiencies and cost savings, but may also reduce competition.

The GAO was candid about the limits of available evidence. "Limited information was available to assess the effects of concentration and vertical integration in private dental and vision insurance markets," the report states. Auditors identified only two peer-reviewed studies examining dental insurance market concentration, which found reduced reimbursements to providers in more concentrated markets. Industry interviewees reported that concentration limits providers' ability to negotiate contracts and reimbursement rates, though the GAO characterized those accounts as nongeneralizable observations rather than definitive findings.

Stakeholders interviewed during the review raised questions about whether provider contracts, reimbursement structures, or product choices may sometimes be influenced by business relationships within vertically integrated systems.

The data do not automatically establish harm to patients, but they do expose a structural reality that policymakers, employers, and consumers have had little visibility into. With roughly one in four Americans relying on these plans, the question of whether the market offers genuine competition is not academic. The GAO's findings give regulators and lawmakers a data foundation to examine that question more rigorously.